w3resource

PHP: is_scalar() function

Description

The is_scalar() function is used to check whether a variable is a scalar or set or not.
Note :
Variables which contain boolean, double, integer, or string types are scalar. Array, object, and resource are not scalar.

Version:

(PHP 4 and above)

Syntax:

is_scalar(variable_name) 

Parameter:

Name Description Required /
Optional
Type
variable_name The variable being checked Required Mixed*

*Mixed: Mixed indicates that a parameter may accept multiple (but not necessarily all) types.

Return value:

TRUE if variable_name is a scalar, FALSE otherwise.

Value Type: Boolean

Example:

<?php
$var1 = 100;
if (is_scalar ($var1))
echo $var1. ' is a scalar value'.'<br>';
else
echo $var1.' is not a  scalar value'.'<br>';
$var2 = array(1);
if (is_scalar ($var2))
echo $var2. ' is a scalar value'.'<br>';
else
echo  $var2. ' is not a  scalar value'.'<br>';
?>

Output :

100 is a scalar value
Array is not a  scalar value

View the example in the browser

Practice here online :

See also

PHP Function Reference

Previous: is_resource
Next: is_string



PHP: Tips of the Day

SQL injection that gets around mysql_real_escape_string()

Consider the following query:

$iId = mysql_real_escape_string("1 OR 1=1");    
$sSql = "SELECT * FROM table WHERE id = $iId";

mysql_real_escape_string() will not protect you against this. The fact that you use single quotes (' ') around your variables inside your query is what protects you against this. The following is also an option:

$iId = (int)"1 OR 1=1";
$sSql = "SELECT * FROM table WHERE id = $iId";

Ref : https://bit.ly/32q3bJ7